Keyboard for use in signalling systems



Aug. 28, 1962 w. PAUL ETAL KEYBOARD FOR USE IN SIGNALLING SYSTEMS 2 Sheets-Sheet 1 Filed April 8, 1958 8, 1962 w. PAUL ETAL 3,051,799

KEYBOARD FOR USE IN SIGNALLING SYSTEMS Filed April 8, 1958 2 Sheets-Sheet 2 United States Patent Ofifice ensues Patented Aug. 28, 1962 KEYBOARD FOR USE IN SIGNALLING SYSTEMS Walter Paul, Albert Geese, Franz Gaber, and Hans Greska, all of Munich, Germany, assignors to Siemens & Halske Aktiengesellschaft, Berlin and Munich, a corporation of Germany Filed Apr. 8, 1958, Ser. No. 727,222 Claims priority, application Germany Apr. 17, 1957 8 Claims. (Cl. 200-) This invention is concerned with a keyboard device for use in signalling systems, especially telephone systems, comprising a plurality of individually operable key devices forming an operating unit.

The general object of the invention is to provide an improved construction of such a keyboard device so as to simplify the electrical and mechanical assembly operations as well as the adjustment operations and further, to reduce the space requirements.

There are keyboard devices known having contact spring banks composed of strips or bars consisting of a contact frame and surmounted by a mounting frame. The mounting frame serves for the joumalling of the keys and carries mechanical control members, the contact spring sets being placed in the contact frame, and the plungers of the keys extending through both frames. These constructions were intended to facilitate the assembly of the key bars as well as accessibility thereto and also to facilitate the exchangeability of the contact spring sets. However, since the contact spring sets are individually secured in place by means of special mounting elements, a great number of individual parts is required in these known structures, and the adjustment of the contact springs with respect to their mutually cooperating positions is rendered ditficult. The interconnection of individual contact spring sets, whenever necessary, requires wiring material and corresponding soldering as well as testing operations. These disadvantage become particularly noticeable in the case of contact spring bank in which several such key bars are combined to form a unit, for example, in the case of a key transmitter structure which must be accommodated within relatively small housings and containing involved interior wiring.

It is known from multipled contact banks of switches, such as selector switches, to punch contact elements layerwise from an integral metal sheet. Such elements, being interconnected by webs, are assembled in layers, the webs forming thereby the multiple wiring. Separate multiple wiring and those of the adjustment operations which determine the mutual positions of the contact elements of a layer, are thus eliminated.

The above indicated general construction of punched contact elements is according to the invention utilized in connection with contact spring banks for keyboards comprising individually operable keys, combined in a unit, thereby eliminating the previously noted disadvantages of prior contact spring bank structures. This object is achieved by the provision of contact springs cooperatively associated with the keys, such contact springs forming part of an interrelated contact multiple connected together by means of webs which are arranged and constructed so that at least portions thereof constitute in the assembled condition of the multiple at least part of the interior wiring required for the keyboard. All contact springs of a layer, in given cases together with the respectively associated multiple wiring, and at least part of the interior interwiring, for example, connecting bridges, are thus made of one piece. Adjustment operations for positioning the individual parts in a layer each with respect to the other and a considerable part of the work required for the interior wiring, are in this manner eliminated. The number of parts required is reduced, thereby facilitating disposal of the contact spring banks in small housings, which until now occasioned great difficulties, for example, in connection with key selectors built into subscriber stations.

The inten'or wiring of the contact spring banks, especially in the case of key selectors, may also include connections between contact springs associated with different keys. In accordance with the invention, the webs interconnecting the contact spring elements may be constructed and arranged so as to produce web grids between contact springs which provide for the desired interconnections. These web grids impart to the corresponding punched contact layers great mechanical strength, thus avoiding difliculties in the production, handling and assembling thereof, despite the relatively large area covered thereby along which the contact spring sets are distributed twodimensionally.

Further compact disposal of the parts may be obtained by placing the contact springs of the multiple so as to extend alternately in opposite directions. The terminal ends of the contact springs which extend in identical direction are thereby interconnected by means of a web and these webs are interconnected by means of a transverse web extending preferably between and in parallel with the contact springs. These webs give the possibility for many different interior wiring schemes and permit reduction of the number of terminal wires for the key banks, for example, in the case of a key selector, to reduce the number of terminal wires to that involved in a dial.

The construction of the contact spring banks according to the invention also facilitates the disposal thereof within a housing. In case of a keyboard comprising a plurality of keys, an arrangement in two parts which facilitates accessibility and exchangeability, may be particularly advantageously utilized. In such arrangement, the contact spring multiples are disposed within a downwardly open space formed by a first bridge-like mounting plate made of insulating material, such mounting plate being surmounted by a second mounting plate preferably likewise made of insulating material, further contact spring sets being disposed within the space extending between the top side of the first mounting plate and the bottom side of the second mounting plate, and vertically aligned openings being formed in such mounting plates for receiving and guiding the key plungers extending downwardly therethrough.

The various objects and features of the invention will appear from the description of an embodiment which will be rendered below with reference to the accompanying drawings. In the drawings,

FIG. 1 shows a keyset according to the invention as seen from the front;

FIG. 2 is a sectional view along the line A-B of FIG. 1;

FIG. 3 represents a bottom view looking at contact spring banks disposed in the space extending below one of the mounting plates therefor FIG. 4 shows contact spring sets disposed within the space extending between the two mounting plates;

FIG. 5 is a fractional view illustrating a key comprising a plungerlike member extending through and guided within vertically aligned openings formed in the two mounting plates; and

FIG. 6 is a part sectional side view of the key bank.

Referring now to FIG. 1, there is provided a bridgelike mounting plate 1 surmounted by a similar bridgelike mounting plate 2. The mounting plates 1 and 2 are provided with respectively vertically aligned openings formed therein for receiving and guiding plungerlike actuating members 3 respectively extending from keys in the rows of keys 4 and 5. Upon the underside of the mounting plate l are disposed contact spring sets to be operatively affected by the actuating members 3 extending from the respective keys, such contact spring sets resting respectively against stepped sockets 6; further contact spring sets It for particular purposes, being disposed between the space extending between the top side of the base plate plate 1 and the bottom side of the base plate 2 as shown in FIG. 4. The individual keys are arranged in two rows 4 and 5, one in back of the other, the actuating members 3 extending from the keys in the back row being longer than those extending from the keys in the front row. Numeral 19 in FIG. 2 indicates the cover for the key bank.

The contact springs of the contact sets disposed underneath the bridge portion of the mounting plate 1 are formed in groups each interconnected by a web such as 8 (FIG. 3) constituting a multiple therefor and the groups are interconnected by transverse webs 8. These groups of multipled springs are assembled in layers to form the respective contact sets. Contact springs which are not to be electrically interconnected may be disconnected from the respective multiple web by cutting out the corresponding portions thereof after the assembly of the contact spring sets is completed. The outer ends of the contact springs may be provided with soldering tabs if desired. Ribs 9 which are integral with the mounting plate determine the lateral positions of the contact springs. The individual contact springs rest against different steps of the sockets 6, depending upon their shape and length, thus forming functionally different contact sets.

The manner of guiding the plungerlike actuating members 3, extending from the respective keys, in corresponding vertically aligned opening formed in the mounting plates 1 and 2 is apparent from FIG. 5. The illustrated key, marked by numeral 1 belongs to the back row 4 (FIGS. 1 and 2) of keys which also includes the keys marked by numerals 2 to 5. The plungerlike actuating members are of generally cylindrical shape, carrying at the lower end thereof a lateral extension or ear 11 which is upon insertion of the key passed through a cutout 12 extending laterally from the circular hole in the base plate 2, entering a similar lateral cutout extending from the circular hole 13 in the base plate 1. The lateral cutouts 12 in the two base plates 2 and l are angularly mutually displaced, thus preventing inadvertent dropping out of a key from the keyboard.

Referring now to FIG. 6, showing the key bank in side view with parts in section, numeral 14 indicates a rocking member journalled upon knife edges formed by member 15 and held in place by means of a resilient bracket 16. Extensions 20 of the rocking member 14 project downwardly through openings in the upper base plate 2 for actuating the contact spring sets 10 (FIG. 4) disposed within the space between the two base plates. The rocking member 14 is actuated by the individual keys in the two key rows, each key 17 of the front row, upon actuation thereof, tipping the rocking member 14 clockwise, as seen in FIG. 6, and each key of the back row being provided with a camming member 18 which is upon actuation of such a key operative to tip the rocking member 14 counterclockwise. The extensions 20 carried by the rocking member 14 are incident to the tipping thereof correspondingly moved to actuate contact springs such as 10, shown in FIG. 4. The plungerlike actuating members 3 of the keys in the back row 4 (FIGS. 1 and. 2) are longer than the corresponding actuating members of the keys in the front row (FIGS. 1 and 2) and the faces of all keys are, therefore, clearly visible from the front of the keyboard.

The plungerlike actuating members of the keys are guided within the openings in the base plates with suflicient play to prevent binding of the keys in their openings in the cover 19 (FIG. 2) upon actuation of the keys.

Changes may be made within the scope and spirit of the appended claims.

We claim:

1. A keyboard for use in a communication system, having a plurality of respectively individually operable keys assembled to form a unit, contact springs disposed in layers forming sets of contact springs respectively cooperating with the respective keys, the contact springs included in each layer being formed from a punched sheet and interconnected by webs to form a contact spring multiple therefor, said webs being disposed to connect two respective springs in series and pairs of springs in parallel, said webs being severable with retention or removal of selected webs determining the conductive interconnections between said springs in accordance with at least part of the interior wiring of said keyboard.

2. A keyboard according to claim 1, wherein the contact springs extending in the multiples in alternately opposite directions are internestled, the ends of the contact springs extending in identical direction being respectively interconnected by a web and at least one transverse web extending substantially parallel to said contact springs for interconnecting said first noted webs.

3. A keyboard according to claim 1, comprising a first bridgelike mounting plate forming a downwardly extending space for receiving said contact spring multiples, a second bridgelike mounting plate disposed above said first mounting plate forming with the top side of the latter plate another space for receiving further contact sets, plunger-like actuating members extending respectively from the respective keys through holes formed in said mounting plates for operatively actuating said contact sets.

4. A keyboard according to claim 3, comprising lateral ribs and partially stepped socket means respectively carried by said mounting plates for cooperation with the respective contact spring sets in accordance with the operative function thereof.

5. A keyboard according to claim 3, wherein the holes formed in the respective mounting plates have recesses extending laterally therefrom in angularly different directions, said actuating members having positioning bosses extending laterally therefrom for passage through said recfises upon placing the respective keys into position on the keyboard.

6. A keyboard according to claim 3, comprising a knife-edge-journalled rocking member disposed upon said second mounting plate, said rocking member constituting a switching element and the arms thereof extending into the path of actuating motion of at least some of said keys.

7. A keyboard according to claim 6, comprising spring means for holding said rocking member in assigned position journalled upon said knife-edge.

8. A keyboard for use in a communication system, having a plurality of respectively individually operable keys assembled to form a unit, contact springs disposed in layers forming sets of contact springs respectively cooperating with the respective keys, the contact springs included in each layer being formed from a punched sheet and interconnected by webs to form a. contact spring multiple therefor, said webs being disposed to connect two respective springs in series and pairs of springs in parallel, said webs being severable with retention or removal of selected webs determining the conductive interconnections between said springs in accordance with at least part of the interior wiring of said keyboard, a first bridgelike mounting plate forming a downwardly extending space for receiving said contact spring multiples, a second bridgelike mounting plate disposed above said first mounting plate forming with the top side of the latter plate another space for receiving further contact sets, plunger-like actuating members extending respectively from the respective keys through holes formed in said mounting plates for operatively actuating said contact sets, a knife-edge-journalled rocking member disposed upon said second mounting plate, said rocking member constituting a switching element and the arms thereof extending into the path of actuating motion of at least some of said keys, said keys being arranged in two horizontally extending rows, the plunger-like actuating members of the keys of the rearwardly positioned row being longer than those of the keys of the forwardly positioned roW and being respectively provided with a lateral extension the lower edge of which cooperates with one arm of said rocking member, the lower edge of the respective keys in the forwardly positioned row cooperating with the other arm of said rocking member.

References Cited in the file of this patent UNITED STATES PATENTS Raynolds Sept. 3, 1918 Luther Nov. 1, 1932 Bierenfeld Mar. 24, 1936 Hartley Aug. 6, 1946 Arthur- Dec. 4, 1951 Cohen Sept. 1, 1953 Rucks et a1. July 12, 1955 Tong -2 Nov. 12, 1957 Graybill et al Feb. 25, 1958 Bentzman May 5, 1959 Dubois Jan. 24, 1961 

